The subject of the present invention is a heating, ventilation and/or air conditioning apparatus, particularly but not exclusively for a motor vehicle, including one or more flaps controlled by a control device.
At the present time, remote controls via sheathed cable for one or more flaps are fit onto a destination casing by clamping the sheath of the cable using clamps. The clamps must be placed judiciously, generally by experienced operators, so that the flap can be controlled optimally, that is to say while ensuring leaktightness on each of its bearing surfaces.
This operation is called the setting-up of the remote control. At the present time, an operator is obliged to carry out the setting-up since, because of dimensional dispersion of the components of control linkage, it is not possible to obtain optimal operation while always positioning the remote control at the same place on the casing.
Incorrect positioning of the sheath on the casing may cause what is known as the spring effect.
This is manifest as inconvenience for the user, who can not manage to set the knob of the control panel at its end stop. This happens because, when the knob is turned to the end stop, the flap arrives at its end stop before the knob of the control panel. As a result the kinematic linkage is deformed (buckling of the cable, bending of the flap, twisting of the lever, etc.) thereby creating a resisting torque which, if it is greater than the latching torque of the control panel, (i.e.) the torque holding the knob in one position or notch of the control panel, and which must be overcome in order to release the knob from the notch for shifting tends to make the knob come out of its end-stop position, hence the spring effect.
It is, obviously, possible to avoid this spring effect:
either by increasing the travel of the flaps for the same travel of the control knob, which widens be setting-up range, but exhibits the major drawback of substantially increasing the admissible leakage;
or by increasing the latching torque when the control knob reaches its end stop, which gives rise to poor uniformity, since the forces are small except when the knob comes to the end stop, and may be countered only by increasing the overall forces on the control knob.
French Patent Application No 2 737 864 (BEHR) describes a closure flap intended to guarantee reliable leaktightness in the closed position of the flap, despite the relatively large discrepancies in position of the flap. To this end the flap exhibits a sealing lip arranged on the outer side of a part of the flap which forms a frame, and linked to the inner body of. The flap by means of an elastic linking element. The operating forces of the flap are transmitted to the inner body by means of an elastically deformable coupling element.
French Patent Application No 2 679 621 filed by the Applicant proposes a device for control of two flaps which are actuated remotely by the same control means. In order to absorb any manufacturing and/or assembly tolerances which are likely to induce an undesirable angular offset of the flaps, while ensuring leaktight blocking of the orifices, the device proposes to link at least one of the flaps to its control means via a flexible coupling, which consists of an elastomer sleeve that provides an elastic link between the control shaft and the spindle of the flap.
The solutions proposed by the two references are not specifically designed to dispense with the setting-up and avoid the spring effect. The references amount to taking action on the range of adjustment of the exhibiting the drawback of fluttering of the flap during variations in the dynamic pressure, by reason of the elastic coupling between the flap and its control shaft.
The subject of the Patent Application GB 2 322 181 (ITW ATECO) is an actuating device in which the control knob is not coupled directly to the flap. On the contrary, this coupling is achieved indirectly with a rotary damper which includes a rotor and a pinion which are housed in a cylindrical receptacle filled with a damping liquid such as silicone oil, in such a way as to create a given friction force which has to be overcome when the pinion is activated. The problem this system aims to resolve is that of noise which the rapid closing of a flap produces, and this problem is resolved by the combination of the abovementioned rotary damper and a lever with two arms. This two-armed lever has a first arm consisting of an elastic strip and a second arm consisting of a toothed sector which drives the pinion of the rotary damper.
When the device is actuated, the elastic strip starts to bend by reason of the damping torque of the damper, until this torque is overcome, resulting in a retarded and damped control of the flap.
It will be noted that, in this system, there is no one-to-one correspondence between the position of the knob and the position of the flap by reason of the slippage introduced by the rotary damper.
The operation of this device implies an initial storage of energy (at the start of the actuation) which is then recovered at the end of travel.
This energy storage and recovery process, with the losses which result therefrom, particularly in the rotary damper, require an increase in the force exerted on the knob.
The device described in the Patent Application GB 2 322 181 also has the drawback of being complicated, since it implies the addition:
of a very flexible lever with large range of travel which has to be dimensioned to store and return the energy required to cause the flap to close at the end of travel; and
of a rotary damper.
None of the devices analyzed above is therefore capable, without conspicuous drawbacks, of resolving the problem of the spring effect, and of dispensing with the setting-up of the remote control.
An aim of the invention is at least partly to remedy the spring effect by reducing the resisting torque, for a given deformation of the system, by the introduction of an elasticity remote both from the flap in order to avoid the abovementioned drawbacks, as well as from the control panel in order to avoid introducing flexibility thereto which would cause an effect simular to the spring effect which is sought to be eradicated. That being so, the troublesome effects induced by the introduction of elasticity into the kinematic linkage are masked by friction in the kinematic linkage.
If the deformation of the system can be managed without generating the spring effect over a distance which is greater than or equal to the dimensional dispersion on the components of the linkage, then it is permissible to dispense with the setting-up by always positioning the remote control at the same place on the casing, and particularly by replacing the clamp by a clip delivered with the remote control.
The invention relates to a control device for at least one flap, including a control member and a kinematic control linkage of the direct-coupling type, arranged between the control member and said flap. The kinematic linkage particularly includes a sheathed cable fixed close to its two ends, wherein the kinematic linkage includes at least one elastic element arranged in such a way as to confer deformability by flexing on the kinematic linkage when a said flap is at its end stop.
The kinematic linkage generally includes: 1) a first lever the movement of which is controlled by the control member and which includes a first receiver element including a housing that accommodates an upstream end of the cable and/or 2) a second lever which includes a second receiver element including a housing that accommodates a downstream end of the cable in order to control the movement of the second lever, that drive said flap in rotation about an axis of rotation. At least one said lever may include a said elastic means.
According to a first variant, this elastic means is advantageously an elastic arm, which is arranged between said receiver element and a central region of the lever. This elasticity can be obtained either by modifying the cross-section of the component over a certain distance, or by overmoulding the component with an elastic material such as an elastomer.
According to a preferred embodiment, the device exhibits two end stops situated on either side of the elastic arm so as to obtain an effective end stop to the movements of the elastic arm on either side of their rest position.
According to a second variant, at least one said lever exhibits two elastic arms arranged between said receiver element and a central region of said lever. Preferable, the central region of the lever exhibits an elongation arranged between said two elastic arms so as to obtain an effective end stop to the movement of the elastic arms on either side of their rest position.
According to yet another embodiment, at least one end of the cable is coupled elastically to the corresponding receiver element.
The deformation by flexing as perceived at the level of the cable advantageously lies between 0.15 mm/N and 0.3 mm/N.